In pressing the case against James Eagan Holmes, the man accused of one of the worst mass shootings in American history, Arapahoe County prosecutors made it clear Monday they were leaving little to chance.

Holmes, 24, was formally charged with a total of 142 criminal counts — including two separate allegations of murder for each of the 12 people who died in the July 20 attack at the Century Aurora 16.

The two murder charges are based on different legal theories.

Prosecutors similarly filed two counts of attempted murder for each of the 58 people who were injured in the attack, carried out during an early morning premiere of the new Batman movie, “The Dark Knight Rises.”

All told, Holmes faces 141 felonies: 24 counts of first-degree murder, 116 counts of attempted murder and one count of possession of an explosive device. Holmes, 24, was also charged with one “sentence enhancer” count for allegedly committing a crime of violence.

In the murder and attempted-murder charges, Holmes was accused in half the counts of committing the crimes after deliberation and in the other half with committing them with extreme indifference.

Denver attorney Daniel Recht said the different counts are an advantage to prosecutors because if a jury were to acquit Holmes under one theory, it could still convict him under the other theory. Extreme indifference, Recht wrote in an e-mail, is “arguably a much easier mental state for the prosecution to prove.”

If convicted of any of the murder charges, Holmes could face execution, though prosecutors have not yet said whether they will pursue the death penalty.

The most lenient sentence Holmes could receive if convicted of the murder counts is life in prison without parole.

In a statement issued after the hearing on behalf of the family of shooting victim Jonathan Blunk, his cousin Jessica Watts said Blunk’s family has faith the district attorney’s office will “pursue all applicable charges” against Holmes.

“He will be held accountable for his actions and we, Jonny’s family, will continue to mourn the hole we now have in our lives,” Watts said in the statement.

In a charging document unsealed after the hearing, prosecutors accuse Holmes of one count of murder after deliberation and one count of murder with extreme indifference for each of the 12 victims who died.

The attempted-murder charges follow a similar pattern — officials have said 58 people were wounded in the shootings but have not released a list of names. The charging document muddies the picture somewhat.

The document listed wounded survivor Bonnie Kate Pourciau twice, in two charges naming a victim Bonnie Kate and in another two charges naming a victim as Bonnie Pourciau. Officials at the District Attorney’s office said they could not clear up the confusion, citing a judge’s order limiting publicity.

“Because of the gag order, our office is unable to interpret the charging document at this time,” said Casimir Spencer, a spokeswoman for District Attorney Carol Chambers.

The charging document also included the names of several shooting survivors who were not physically injured and did not include the names of some of those who were wounded and survived.

Recht, the Denver attorney, said attempted murder is a valid charge in cases where people are shot at but not hit. He said prosecutors likely made their charging decision after talking to victims and ensuring they were comfortable with being included in the case. More so, Recht said, prosecutors likely didn’t want to charge Holmes with every possible crime he could be charged with, such as aggravated assault.

“Clearly the prosecution decided they needed to keep this to the most serious charges,” Recht said. “They wanted to keep the jury from getting confused with potentially hundreds of counts.”

The charges can be amended in the future.

It was Holmes’ second court appearance — at a preliminary advisement hearing July 23, he looked dazed and drowsy. Monday, Holmes appeared more composed. His hair, still dyed a Kool-Aid orange and red, was combed flat.

For much of the hearing, he appeared to be paying attention, often looking at Judge William Sylvester as he spoke. When Sylvester asked Holmes a question — whether he would agree to waive his right to a preliminary hearing within 35 days — Holmes answered with a muffled, “Yes.”

Media cameras, which had been allowed for Holmes’ first appearance, were not allowed in the courtroom during Monday’s hearing.

In the audience, dozens of shooting survivors and family members of victims looked on, at times leaning forward to listen as Sylvester spoke and at other times craning their necks to look at Holmes.

Shooting survivor Rita Paulina, whose wrist, arm and leg were wrapped in bandages, fidgeted with the gauze and rested her arm awkwardly on the seat.

The next hearing in the case is scheduled Aug. 9, when attorneys will debate a motion from 20 news media organizations to unseal the case file. After that, on Aug. 16, Sylvester plans to hear arguments from the prosecution and the defense over a notebook Holmes allegedly mailed to his psychiatrist. Holmes’ attorneys have asserted that the notebook is privileged doctor-patient communication.

The next major hearing in Holmes’ case will likely be a preliminary hearing, at which the judge will listen to testimony to determine whether there is enough evidence for the case to proceed to trial. That hearing could provide the public with significant new information about the events of July 20. But the hearing, which Holmes’ attorneys said could take a week, isn’t scheduled until Nov. 13.

Even that date could be optimistic, said Denver defense attorney Pete Hedeen.

Given potential mental health issues hinted at publicly, Holmes’ defense team is likely to raise issues of competency to determine whether he is able to participate in his own defense.

Once competency is raised, it stops the clock on the trial while defendants typically undergo at least two rounds of psychological evaluation. A judge makes the final determination, but even a fast-tracked process can take three to five months, Hedeen said.

“Certainly the indications are that this guy is seriously mentally ill,” Hedeen said. “It’ll be interesting at what point will they raise the competency issue.”

The owners of Boulder’s Sterling University Peaks apartments, who this summer were cited for illegally subdividing 92 bedrooms in the complex, have reached an agreement to settle the case for $410,000, the city announced Thursday.